Control for traffic signal systems



s. s. sToLP Erm. '2,234,636 CONTROL FOR TRAFFIC SIGNAL SYSTEMS Filed Aug. A25, 1928 2 Sheets-Sheet 1 .N .UE

March 11, 1941.

March 11g 1941. 5 s STQLP Elf-M 2,234,636

. CONTROL FOR TRAFFIC SIGNAL SYSTEMS Filed Aug. 25, 192s 2 sheets-sheet SET WQ.

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Patented Mar. 1l, 1941 UNITED PATENT OFFICE Louisville, Ky., assignorsto Nachod & United States Signal Company, Inc., Louisville, Ky.

Application August 25,

l Claims.

Our invention relates to the control of electrically-operated traffic signals primarily intended for use at the intersection of thoroughfares.

The main object of our invention is to provide means wherein an electric car approaching the intersection will take control of the traflic signal to prolong a proceed indication to favor the preferential movement of the car. In other words, the traiiic signal will be displaying stop and proceed indications periodically until a car enters a certain predetermined zone with respect'to the intersection, wherein the periodic control of the traine signal indications will be in terrupted, and the display of the proceed indication on the electric line and the stop indication ior the intersecting trafiic prolonged to permit a continuous movement ci the car past the intersection. The system is so arranged that the periodic control is restored alter the car passes the intersection, and when the automatic timer has entered the period for displaying the proceed indication on the E-W electric line.

It will be apparent to those skilled in the art that, since the system does not interrupt the signal periods regulated by the automatic, motordriven time-element of the traic signal control, the system is readily adaptable to the so called wave or platoon system which, at the present time, is extensively used throughout the country.

Our invention resides in a new and novel combination, construction and relation of various electrically operated switches, circuits and other parts hereinafter more fully described and disclosed in the drawing.

In the drawing accompanying our specification:

l is a schematic circuit diagram disclosing the general principles employed in our system.

Fig. 2 is a graphic representation oi a series of signal units operating synchronously.

Our invention is intended primarily to be controlled by cars which are supplied with operating current by means of an overhead trolley wheel or current collector, represented in Fig. l by Wi or W2, although it may be controlled by vehicles operated by other methods.

In the system shown in Fig. 1, the letter D designates a trolley wire or conductor for Westbound car movements. Positioned adjacent this trolley wire D, are trolley contactors 3W and 5W, which contactors are normally insulated therefrom, but electrically connected thereto, when the current collector W2 engages the trolley contactors EWand 5W respectively. The characters 1928, Serial No. 362,020

(El. 17V-33 Dl designate a trolley wire or conductor for eastbound car movements. Positioned adjacent this trolley wire Dl, are trolley contactors 3E and 5E, which ccntactors are normally insulated therefrom, but electrically connected thereto, when the current collector W! engages the trolley contactors 5E and 5E respectively.

At the intersection, the characters TS designate a traiic signal, which signal periodically displays stop, caution and proceed indica- 10 tions for the E-W electric line traffic and the N--S intersecting trahie.

We also employ electrically operated relays R and Rl that are under the control of current collectors engaging the respective trolley contactors. Relay R is provided with two operating coils A and C, and a contact plunger' R. The plunger P is provided with a contact ring A2 that normally engages contacts 28 and 29, and brought into this position by the energization of the coil C. When the coil A is energized the contact plunger P is shifted, and the contact ring A2 is brought into contact engagement with contacts 5t and (it and out of contact engagement with contacts Z8 and 29. Relay Rl is provided with two operating coils AI and Cl, and a contact plunger Pl. The plunger PI is provided with a contact ring A3 that normally engages contacts E2 and 63 and is brought into this position by the energization of the coil Cl When the coil A! is energized the contact plunger PI is shifted, and the contact ring A3 is brought into contact engagement with contacts 3| and 32 and out of contact engagement with the contacts G2 and 63. 35

We also employ an electrically operated relay R2, which relay is controlled by a circuit established thru the relays R and Rl respectively, and certain auxiliary circuits controlled by the motor-driven time-element device controlling the display of the traflic signal indications. The relay Ri is provided with an operating coil L and two contact bridging bars A4 and A5, which bridging bars are insulated from each other. The :coil L of relay R2 is normally deenergized, and the contact bridging bars A4 and A5 normally engage their respective back contacts til- 4I and tit-5l. When the coil L is energized, the contact bridging bars A4 and A5 are raised, and removed from contact engagement with their respective back contacts, and brought into contact engagement with their respective front contacts I2-95 and 52-53.

We also employ a motor-driven time-element device for periodically and cyclically displaying of the signal indications.

"stop, caution and proceed signals. The letter M designates a motor that rotates cam segments C2, C3, C4 and C5, which segments are mounted on a common shaft 95. With reference to Figure l, it will be observed that the rotation of the cam segments in the direction of arroW 91 provides a cyclical opening and closing of various contacts, which contacts control circuits connecting the signal indications.

The outline figure TS is a symbolic representation of a tramc signal comprising three decks of signal indications displaying four directions. In the upper deck, red lenses SI and 82 face N and S on the intersection, and green lenses 83 and 84 face W and E on the electric line, and these have a common light source designated by LI. In the center deck, four lenses 85, 85, 87, and 88 display an amber or caution indication, and each is p-rovided with an independent light source, lens 85 having a light source designated by L4, lens 35 having a light source designated by L5, lens 3l having a light source designated by L2, and lens S8 having a light source designated by L3. The caution indications are not displayed simultaneously, but are displayed at intervals that Will be fully described later in the description. In the lower deck, green lenses 8S and e8 face N and S on the intersection, and red lenses 9i and 92 face W and E on the electric line, and these have a common light source designated by L5. For clarity of the description each of the three decks are shown in a plan view, and this must be taken into consideration When the description is read, so that the display of the signal indications will be understood properly.

The indications of the traffic signal are normally displayed cyclically; that is, each indication displays a certain predetermined time before a display of another signal indication occurs, all of which occurs in a definite sequence of a predetermined cycle. Starting for instance at an arbitrarily selected time of the cycle, We have a display of a green signal in both directions for the W and E electric line trafc, and a red signal in both directions for the N and S intersecting trafiic. The circuit for these indications is completed from the positive side of the line BX, thru wire l, Wire I3, contact arm I4 of the motordriven time-element, contact I5, contact I5, thru the stationary contact arm I'l, Wire I8, Wire I9, Wire 28, wire 2l to the signal lamp LI, which lamp is a common light source for the four indications, wire 79, Wire 2, Wire I to the common return of the line CIK. With reference to Figure l, it will be observed that these indications Will display as long as cam segment C2 retains contacts I5 and Iii engaged, which is for one half of the total cycle. It will also be observed that just as the cam segment C2 nears the end of its period, cam C3 actuates Contact arm 23, which actuation brings contacts 24 and 25 into Contact engagement, and an amber caution signal is displayed to Warn the east and West bound tralc that a change is about to be made in the display As previously mentioned, the caution indications are not displayed simultaneously to all traii'ic, but only to the traffic receiving the proceed indication. The circuit for the E-W caution indication is completed from the positive side of the line BX, thru wire 1, Wire 8, Wire 22, contact arm 23 of the motordriven time-element, contact 24, contact 25 thru the stationary contact arm 26, wire 2l, contact 28 of relay R, Contact ring A2, contact 29, Wire 30,

contact 62 of relay RI, contact ring A3, contact 63, Wire 64, Wire 65, to the lamp L2, which lamp is the light source for lens 8l facing the W electricI line traflic. It 'vvill be noted that wire 54 connects two branch circuits, one connection to wire 6-6 as described, and the other to Wire 65 which feeds the light source for the lens facing the E electric line trahie. The circuit for the latter is completed from Wire 64 to the branch wire 65, thru Wire 65 to the lamp L3, which lamp is the light source for lens 88 facing the E electric line traic. Both lamps L2 and L3 have a common connection to the common return thru Wire 89, wire 3, Wire 2, Wire I, to the common return of the line CX. Cams C2 and C3 disengage their respective contact arms simultaneously, and instant to this operation, cam C5 actuates contact arm 45, which actuation brings contacts 4'I and 48 into contact engagement. These operations extinguished the former indications, and displayed a red indication for the E-W electric line traiTlc and a green indication for the NS intersecting traic. The circuit for the E--W red and N-S green indications is completed from the positive side of the line BX, thru wire 1, Wire 8, Wire 9, Wire I0, Wire 45, contact arm 48 of the motor-driven time-element, contact 4l, contact 48, thru the stationary contact arm 49, Wire 55, wire 55, contact 56 of relay R2, contact bridging bar A5, contact 5l, Wire 58 to the signal lamp L6, which lamp is the common light source for the four indications, wire 4, wire 3, Wire 2, wire I, to the common return of the line CX. With reference to Figure 1 it will be observed that these indications will display as long as cam segment C5 retains contacts 47 and 48 engaged, which is one-half of the total cycle. It will also be observed that just as the cam segment C5 nears the end of its period, cam C4 actuates contact arm 35, which actuation brings contacts 38 and 3l into contact engagement, and an amber caution indication is displayed to warn the N-S intersecting traffic that a change is about to .be made in the display of the signal indications. tion indications are not displayed simultaneously to all traffic, but only to the Itraiic receiving the proceed indication. The circuit for the N-S caution indication is completed from the positive side oi" the line BX, thru Wire 1, wire 8, wire 9, Wire 34, contact arm 35 of the motor-driven time-element, contact 36, contact 3l, through the stationary contact arm 38, Wire 39, contact 40 of relay R2, contact bridging bar A4, contact 4I, Wire 42, Wire 44 to lamp L5, which lamp is the light source for the lens 86 facing the S intersecting trahie. It will be noted that wire 42 connects two branch circuits, one connection to Wire 44 as described, and the other to wire 43 which feeds the light source for the lens facing the N intersecting traffic. The circuit for the latter is completed from the Wire 42 to the branch Wire 43, thru wire 43 to the lamp L4, which. lamp is the light source for the lens 35 facing the N intersecting traffic. Both lamps L4 and L5 have a comrnon connection to the common return thru Wire 80, feeding to wire 3, thru the Wire 3, wire 2, wire I, to the common return of the line CX. Cams C4 and C5 disengage their respective contact arms simultaneously, and instant to this operation cam C2 actuates contact arm I4, and the cyclic display of the signal indications is repeated.

In the description of the car control of the traffic signal indications, we will rst take into As previously mentioned, the oauconsideration a single car movement eastbound. When the current collector Wl engages the trolley contactor 3E, coil A of relay R is energized, thereby shifting plunger P of relay R and bringing contact ring A2 into contact engagement with contacts 68 and E9 and out of contact engagement with contacts 28 and 29. The circuit for the energzation of coil A is completed from the trolley wire Dl, thru the current collector Wl, thru the contact strips of the trolley contactor 3E, wire 15, coil A of relay R, wire 1I, to ground G. As soon as the current collector dislengages the trolley contacter, the coil A of relay R is deenerg-ized, but the plunger P remains in f its shifted position.. The sluiting of plunger P opened .the circuit of the E-W caution indication, normally completed through contacts 28 and 29, and closed a circuit through contacts 68 and 6B. 'I'his operation will not affect the display oi the signal indications, unless the signal was displaying the E--W caution indication, or not until the timer passes thru the necessary cycle to establish this circuit. After the automatic, motor-driven time-element device passes thru the necessary cycle to provide a display of a green indication for the E--W electric line traffic and a` display of a red signal indication for the N-S intersecting traino, the coil L of relay R2 is energized. The circuit for the en.- ergization oi coil L is completed from the positive side of the line BX, thru Wire 1, wire I3, contact arm I4 of the motor-driven time-element, contact I5, contact I6, thru the stationary contact arm I1, wire I8, Wire 1l), Contact 69 of relay R, contact ring A2, contact 68, Wire 61, wire till, wire 59, coil L of relay R2, Wire 94, wire I to the common return of the line CX. The energization of the coil L of relay R2 raised the Contact bridging bars A4 and A5 out of engagement with their respective back contacts and brought them into contact engagement with their respective iront contacts, as hereinbefore described.

Since the aforesaid circuit is completed through contacts Ill-I6 controlled by cam C2 and the contacts Gil- 59 of relay R, it will be apparent that the coil L of relay R2 will not become energized, unless relay R is operated by coil A thereof, and not until the cam C2 Closes contacts lli-i6.

As previously described, cam C3 actuates contact arm 23 and brings contacts 24--25 into engagement shortly before the cam C2 nears the end ci its time of engagement with contact arm it. However, with relay R operated by coil A, the contacts 2%3--28 are disengaged, and the E-W caution indication will not display.

As hereinbefore described, cam C actuates contact arm llt, and brings contacts 41 and 48 into contact engagement, as soon as cams C2 and Cil disengage their respective contact arms. It will be observed that contacts 41 and 48 normally control the circuit for4 the E--W red and N-S green indications, but since the contact 'bridging bar A5 of relay R2 is out of contact engagement with its back contacts 56 and 51, this signal circuit is open, and the indications; are not displayed. The opening of contacts I5 and It, which contacts arecontrolled by cam C2, opened the pickup circuit of coil L of relay R2, but the coil remained energized by reason of a stick circuit cornpleted through front contacts I235 of relay R2, Likewise, the E-W green and N--S red indications, continued to display by reason of a circuit completed through contacts I2-95 of relay R2. The stick circuit for the coil L of relay R2 is completed from the positive side of the line BX thru wire 1, wire 8, Wire 9, Wire I8, wire II, front contact I2 of relay R2, contact bridging bar A4, front contact 95, Wire 93, wire 20, wire I9, Wire 10, Contact 69 of relay R, contact ring A2, contact 68, wire 61, wire 6U, wire 59, coil L of relay R2, wire 94, wire` I, to the common return. of the line CX. The circuit for continuing the display of the E-W green and the N-S red indications is completed from the positive side of the line BX thru wire 1, Wire 8, Wire S, Wire Il), wire II, front contact I2 of relay R2, contact bridging bar A4, iront contact 95, wire 93, wire 2l to the signal lamp LI, which lamp is the light source for the four indications', Wire "i9, wire 2, wire I, to the common return of the line CX. It can be seen that as long as the coil L of relay R2 remains energized, the E--W green and the N-S red indications, will continue to display as hereinbeiore described.

As soon as the trolley car passes the intersection, the current collector WI engages trolley contactor 5E, and the coil C of relay R is energized. The circuit for energizing coil C is completed from the trolley wire Dl, through the current collector WI, through the contact strip of the trolley contactor 5E, wire 16, coil C of relay R, wire 12, to the ground G. The energization of the coil C restores relay R to normal.

Restoring relay R to normal opens the pick-up o and stick circuits for relay R2 completed through contacts 63 and B9 of relay R. However, if the automatic, motor-driven timer has entered the period for displaying the E-W red and N-S green indications, the coil L oi relay R2 will not be de-energized, as a holding circuit is established through contacts 41 and 43 of the motordriven time-element, to retain the coil L of relay R2 energized, and thus continue the display of the lll-W green and N-S red indications until the automatic, motor-driven timer enters the period for displaying the E--W green and N-S red indications, wherein the periodic control is restored to the automatic, motor-driven timer. The aforesaid holding circuit for coil L is completed from the positive side of the line BX thru wire l, wire 3, wire 9, wire Ill, Wire 45, Contact arm 4t of the motor driven time element, contact 4l, contact 48, thru the stationary contact arm 49, wire 50, wire 5I, front contact 52 of relay R2, contact bridging bar A5, contact 52, wire 54, wire 5S, coil L of relay R2, Wire 34, Wire I to the common return of the line CX. As longbas the coil L of relay R2 remains energized by reason of the latter mentioned holding circuit, the E--W green and N-S red indications Will continue to display as hereinbefore described. As cam C5 approaches the end of its time of engagement with the contact arm 46, cam C4 embraces the contact arm 35 and brings contacts 36 and 31 into contact engagement. However, no caution signal circuit is established, as this circuit is open by reason of the bridging bar A4 oi relay R2 being out'l of engagement with its back contacts Mi and 4I. As soon` as the cam C5 disengages the contact arm 45, the holding circuit for the coil L of relay R2 is opened and the contact bars A4 and A5 are restored to normal. Restoring contact bridging bars A4 and A5 to normal, results in the entire system being restored to normal, and under the sole innuence of the motor driven time element. It will be noted. however, that the green W--E electric line indication and the red N--S intersecting traic indication continued to display CII usr

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even after the car has passed the intersection. This display is under the influence of the cam C2 of the motor driven time element, and the purpose of this arrangement is to permit the traflic that was following the car, or held by the car stopping at the intersection, to have time to cross the intersection.

In the latter description only the control of an east-bound car was taken into consideration. However, the control of the traffic signal will function similarly if a car moves westbound and operates relay RI under the influence of trolley contactors 3W and 5W.

A further advantage accomplished in this System is that since the periodic timing of the indication is not interfered with, but only the circuits connecting the indications altered to provide a display of the W-E electric line green indication and the red N-S intersecting traffic indication during that period of the cycle when the automatic timer would have provided a red indication for the E -W tralic and a green indication for the N-S traffic, any number of these traiiic signal control units can be operated in synchronism by having their motor driven time elements adjusted for the same total cycle time with their corresponding periods regulated accordingly.

In Fig. 2 the timing of a group of signals operating synchronously is graphically represented. For simplicity the railway car and vehicular traino are considered in one direction only, namely, eastbound. In the diagram, streets are arranged to intersect the electric railway at 880 feet intervals and the timing of the traflic signals located at each of the intersections is so arranged that all vehicles traveling at a speed equivalent to 20 M. P. H. can travel in a traiiic lane thirty seconds wide and receive a green signal indication at each intersection.

This system of synchronous traflic control is widely used at the present time and is known as the wave or platoon system. As it is Well known to those versed in the art, a system so timed for a certain speed will have several other lanes in which traiiic may move at other speeds and always receive a green signal. These speeds are always less than the maximum arranged speed and in this instance are 61/2 miles per hour and 4 miles per hour, For convenience, the sixty second line X, Y, of the graph has been calibrated in miles per hour, so that all lines intersecting this line extending from the zero point will indicate the relative speed represented by that line. It can be readily seen from the graph that all vehicles moving at speeds other than the synchronous speeds will receive red signals at most of the intersections or all of them, depending upon the rate of speed at which the vehicles move. This is very detrimental to the use of this type of signaling especially during the peak operating hours of the railway cars. During these peak hours the average Speed of the railway car is considerably reduced, and by reason of the varying loading time and speed, trafiic stagnation of vehicles following the car usually results, and, as the car continues its course of travel through the signaled area, a considerable accumulation of the bottled traffic in the rear of the car results.

In the graph the heavy dot-dash lines L represent a railway car starting at the beginning of the system traveling at a speed less than the maximum synchronous speed, thereby arriving at the beginning of the red period at each successive street intersection. At each of these intersections the railway car will be compelled to make a long objectionable stop and. unnecessarily interfere with the progress of the vehicular trafc on that highway. From the latter it can readily be seen that if each of the signaled intersections were equipped with a relay system to control the display of the traflc signal indications, as heretofore described, the long objectionable stops would be eliminated, and the bottled traic would be given a green signal to move on. 'Ihis in eifect is the same as opening an intermediate traiiic lane in the system when a certain class of vehicles interfered with the synchronous speed travel of the system. On the graph the medium dot-dash lines K indicate the travel of a railway car in an intermediate traic lane produced by a relay system controlling the traine signal indications in accordance with the movement of the car. It can be seen that a car starting at zero will move for the rst block in a line corresponding with L and instead of receiving the ordinary red signal at the first intersection, the preceding green period at that intersection would be prolonged by the passage of the current collector Wl of the car under the starting contactor 3E and a red indication removed as represented by the heavy dotted line in Fig. 2. The car then after making a loading stop is enabled to start immediately and clear the intersection on the prolonged green period. If it continues at this same rate of speed, it will clear the second intersection within a normal green period and the normal operation of the traffic signal will not be interfered with. However, at the fourth intersection it would have received a red indication, but with the use of the suitable control device at this location, the preceding green period would likewise be prolonged and the red indication removed as represented by the heavy dotted line in Fig. 2 so that the car might also clear this intersection with the attendant advantages. It can be seen that the intermediate channel K can vary over wide limits and is governed entirely by the speed of the car. For instance, if the car is traveling at a faster rate of speed, the lane will either coincide with the maximum traino lane or neighbor it closely. Likewise if the car is moving at a much slower rate of speed, the .3

trafiic lane will shift in the direction of the slower traino lanes, and through these wide limits the street car will always establish an auxiliary traffic lane to suit-the speed of the car. In addition to the saving of time for the railway car which, by far, handles the greatest percentage of traic, it relieves the tralic congestion that would have ordinarily occurred if the car were compelled to stop at each of the intersections.

It must be understood that at each of the intersections the conventional form of traffic signal is employed, using red, amber, and green signal indications, alternately displayed to the main and cross-thoroughfares. For simplicity only the major indications red and green were considered and only the main line indications were described.

There are, of course, modifications and arrangements of the parts and circuits which may be made from that shown in the above disclosure and which will still fall within the scope of our invention.

We claim:

1. In a trailc control system which comprises iii) a plurality of signal stations each station including a right of way indicating device and a constantly operating device therefor for normally cyclically shifting right of way from one thoroughfare to the other in synchronism with the operation of the remaining signal stations of the system; one of said signal stations including an electrically operated right of way indicating device for the main and cross thoroughiares at said station, a controller means driven by the constantly operating device at the signal station, circuit connections between said controller and the right of way indicating device; a traffic responsive means for said main thoroughfare having one condition of operation when traiiic on said thoroughfare is approaching said intersection and is within a certain distance thereof, and a second cond-ition of operation for all other positions of traflic on said thoroughfare with respect to said intersection, and relay means controlled jointly by the trahie responsive means and the controller means, and having contacts interposed in said circuits between said right of way indicating device and said controller for interrupting the normal cyclic display of the right of way indicating device and for constantly displaying right of way to said main thoroughfare when said trahie responsive means is in said iirst condition of operationand ior restoring 'the cyclic control by the controller means when in said second condition.

2. In a traffic signaling device; an electrically operated right of way indicating device ior main and cross thoroughfare-3s; a constantly operating device; a controller means driven by the constantly operating device; circuit connections between saidcontroller and the right of way indicating device, for normally cyclically shifting right of way from one thoroughfare to the other; a trame responsive means for said main thoroughfare having one condition of operation when trahie on said thoroughfare is approaching said intersection and is within a certain distance thereof; and a second condition oi operation for all other positions of trame on said thoroughfare with respect to said intersection; relay means controlled jointly by the traiiic responsive means and the controller means and having contacts interposed in the circuits between the said right of way indicating device and the controller; for interrupting the normal cyclic display of the right oi way indicating device and for constantly displaying right of way to said thoroughfare when said traiiic responsive means is in said rst condition of operation and for restoring the normal cyclic control by the controller means when the traiic responsive means is in said second condition.

3. A traffic signaling system arranged at the intersection of a main highway and a crossroad for regulating trahie, said system including a highway signal lamp circuit and a crossroad signal lamp circuit, a time controlled switch means normally associated with the said circuits for alternately cylically opening and closing same, relay means controlled by the said time switch means and by a vehicle on the main highway appreachingA the intersection, for maintaining the display of the said highway lamp, and means operable by the said vehicle after clearing the intersection to restore the periodic control of the said signals to the time controlled switch means.

4. A traffic signaling system arranged at the intersection of a main highway and a crossroad for regulating trahie, said system including a highway signal lamp circuit and a crossroad signal lamp circuit, a time controlled switch means associated with the said circuits for alternately cyclically opening and closing same, Vehicular actuated means for the main highway operable to one position when a vehicle enters a certain Zone with respect to the said intersection and a second position when the Vehicle clears the said intersection, and relay means controlled jointly by the said vehicle means and time controlled switch means to interrupt the control of said circuits by the said time controlled switch means and to maintain the display of the said highway lamp for the main highway when the said vehicular actuated means is in the nrst mentioned position.

5. A trafic signaling system arranged at the intersection of a main highway and a crossroad for regulating traffic, said system including a highway signal lamp circuit and a cross road signal lamp circuit, a time controlled switch means normally associated with the said circuits for alternately cyclically opening and closing same, traiiic responsive means actuated by a vehicle on the main highway approaching the intersection and upon clearing the said intersection, relay means having contacts interposed in the said lamp circuits, said relay means controlled jointly by the traffic responsive means and time controlled switch means to interrupt the cony trol of said circuits by the said time controlled switch means and to maintain the display of the highway lamp when the said traffic responsive means is actuated by a vehicle approaching the said intersection and to restore the control 3 to the said time controlled switch means when the said traffic responsive means is actuated by a vehicle clearing the intersection.

6. A right-of-way indicating device for interfering traffic lanes; a constantly operating device, a controller means driven by the constantly operating device; circuit connections between the said controller and right-of-way indicating device, for normally cyclically shifting, right-ofway from one trafc lane to the other, other circuit connections to said right-of-way indicating device for a constant display of the right-ofway to one of the said traiiic lanes, relay means activated by a vehicle, and means operable in response to actuation of said relay means when the right-of-way is displayed to said one lane for shifting from the first named circuit connections to the second named circuit connections whereby the normal cyclic display of the rightof-way is interrupted and the display of the 'i right-of-way to the last mentioned traffic lane is maintained, and means affected by the vehicle for restoring the said relay means to normal whereby the normal cyclic display of the rightof-way is restored.

7. A trahie signaling system for regulating traic on interfering traiic lanes, said system including a right--of-way indication for each of the said traffic lanes, a constantly operating device, and controller means driven by the said constantly operating device, circuit connections between tne said controller and said right-of-way indications for normally cyclically shifting rightof-way from one trahie lane to the other, vehicle operated devices in one of said traflic lanes to be consecutively operated by a vehicle and, means affected by one of said devices when operated by a vehicle to interrupt the normal cyclic display of the said right-oi--way indications and prolong the energization of the right-of-way indication on the said one traic lane a minimum time equal to one complete cycle, and to subsequently restore the normal cyclic control by the first said means when another one of the said devices is operated by the said vehicle.

8. A traiiic signalling system arranged at the intersection of main and cross thoroughfares for regulating traine, comprising a right-of-way indicating device and a time controlled switch means therefor, for normally cyclically shifting the right-of-Way from one thoroughfare vto the other, other means controlled jointly by the said time switch means and by a vehicle on the said main thoroughfare approaching the intersection, for maintaining the right-of-way on the last mentioned thoroughfare for a minimum total period equal to the total time of one complete cycle plus the time of its normal display, and means operable by the said vehicle after clearing the intersection to restore the normal cyclic control by the said time controlled switch means.

9. A traffic signaling system arranged at the intersection of main and cross thoroughfares for regulating traffic, comprising a right-of-way indicating device and a time controlled switch means therefor, for normally cyclically shifting the right-of-way from one thoroughfare to the other, other means controlled jointly by the said time switch means and by a vehicle on the said main thoroughfare, for maintaining the right-ofway on the last mentioned thoroughfare when the said vehicle is approaching the intersection a certain distance thereof, and to restore the normal cyclic control by the said time switch means after the vehicle clears the said intersection.

10. A trairlc signaling system arranged at the intersection of main and cross thoroughfares for regulating traffic, said system comprising a rightof-way indicating device and a time controlled switch means therefor for normally cyclically shifting the right-of-way from one thoroughfare to the other, traflic responsive means actuated by a vehicle on the main thoroughfare approaching the said intersection and restored to a normal condition by the said Vehicle upon clearing the intersection, and means controlled by the said time controlled switch means to maintain the right-of-way on the last mentioned lane when the said traffic responsive means is actuated by a vehicle approaching the intersection and to restore the normal control of the right-of-Way indicating device to the said time controlled switch means only after the said trac responsive means is restored to a normal condition by a vehicle clearing the intersectionl 11. A traflic signaling system for interfering traiiic lanes, said system comprising a right-ofway indicating device and a time controlled switch means therefor for normally cyclically shifting the right-of-way from one trafc lane to the other, other means controlled by the said time switch means and by a vehicle on one of the said traiiic lanes for maintaining the rightof-way on the last mentioned traffic lane for a minimum total period equal to a normal `display of the right-of-way to said one lane increased by the total time of one complete cycle,

l2. In a traffic system for intersecting streets, a right-of-way indication, means displaying said indication to each of said streets for predetermined times for the control of traffic, a vehicle responsive device for one of the said streets and a second means operable upon an actuation of said device for cooperating with the first named means to extend the time of display of said indication to the last mentioned street beyond the time determined by the rst named means, said second means to further extend the time of display of said indication upon subsequent actuations of the said device occurring within predetermined intervals of each other.

13. In a traic system for interfering lanes, a right-of-way indication; means cyclically displaying said indication normally to each of said lanes for predetermined times for the control of traffic; a vehicle-actuated device in one of said lanes; and means, operating in response to an actuation of the said device, and cooperating with the first named means when the right-ofway is displaying to the said one lane, for extending the time of display of the said indication to the said one lane for a period of time equal to the normal time of one complete cycle.

14. A traffic control system for intersecting traic lanes having right-of-way traffic signals for each lane, and circuits for energizing the same; an electric motor operating at a predetermined time rate, and a shaft and switches operated thereby for energizing said signal circuits through continuous successive cycles, in each of which cycles the right-of-way signals for the lanes are energized alternately for predetermined periods of time; means responsive to traffic in one of said lanes; relay means operatively associated with the circuits of the right-of-Way signals for the other of said lanes and the correspending motor-operated switches for controlling connection of the latter, said relay means having a normally de-energized condition for connecting the latter said circuits to the said corresponding switches, and an energized condition for disconnecting the latter circuits from said corresponding switches; an auxiliary circuit for energizing directly .the right-of-way signals for the said one lane, including a switch closed by the said relay means in its energized condition; an operating circuit for the said relay means connected with said traiic responsive means, and including a switch closed by the said shaft in the right-ofway period for the said one lane, for energizing said relay means during said latter period in response to traffic in the said one lane; and a holding circuit for the said relay means, including a switch closed by the said shaft at the end of the right-of-way period for the said one lane, which switch is retained closed by the said shaft until the beginning of the following right-of-way period for the said one lane for retaining the said relay means energized through the cycle until the beginning of the said following right-of-way period for the said one lane.

15. A traiic control system for intersecting traffic lanes having right-of-way signals for each lane, and circuits for energizing the same; an electric motor operating at a predetermined time rate, and a shaft and switches operated thereby for energizing said circuits through continuous successive cycles, ineach of which cycles the right-of-way signals for the lanes are energized alternately for predetermined periods of time; tra-flic responsive means for one of said lanes having one condition of operation when trafiic on the said one lane is approaching the said in'- tersection and is within a certain distance thereof, and a second condition of operation for all other positions of traffic on the said one lane with respect to the said intersection; relay means operatively associated with the circuits of the right-of-waysignals for the other of said lanes and the corresponding motor-operated switches for controlling connection of the latter, said relay means having a normally de-energized condition for connecting the latter said circuits to the said correspond-ing switches, and an energized condition for disconnecting said latter circuits from said corresponding switches; an auxiliary circuit for energizing directly the right-of-way signals for the said one lane, including a switch closed by the said relay means in its energized condition; an operating circuit for the said relay means, including a switch closed by the traic responsive means in its said one condition of operation and a switch closed by the said shaft for the duration of the right-o-way period for the said one lane, for energizing said relay during said latter period; and a holding circuit for the said relay means, including a switch closed by the relay means in its energized condition and a switch closed by the shaft at the end of the right-of-way period for the said one lane, which switch is retained closed by the said shaft until the beginning of the following right-of-way period for the said one lane for retaining the said relay means energized through the cycle until the beginning of the said following right-of-way period for the said one lane.

16. A trafc control system for intersecting traiiic lanes havin-g right-of-way signals for each lane, and circuits for energizing the same; an electric motor operating at a predetermined time rate, and a shaft and switches operated thereby for energizing said circuits through continuous successive cycles, in each of which cycles the right-of-way signals for the lanes are energized alternately for predetermined periods of time; control means responsive to trafc in one of said lanes; relay means operatively associated with the circuits of the right-of-way signals for the other of said lanes and the corresponding motor-operated switches for controlling connection of the latter, said relay means having a normally de-energized condition for connecting the latter said circuits to said corresponding switches, `and an energized conditionv for disconnecting said latter circuits from said corresponding switches; an auxiliary circuit for energizing directly the right-of-way signals for the said one lane including a switch closed by the said relay means in its energized condition; an operating circuit for the said relay means, including a switch closed by response of the control means to trac in the said one lane and a switch closed by the said shaft in the right-of-way period for the said one lane for energizing said relay during said latter period; and a holding circuit for the said relay means, including a switch closed by the relay means in its energized condition and a switch closed by the shaft at the end of the right-of-way period for the said one lane, which switch is retained closed by the said shaft until the beginning of the following right-of-Way period for the said one lane for retaining the said relay means energized through the cycle until .the beginning of the said following rightof-way period for the said one lane.

17. A traino control system for intersecting traffic lanes having right-of-way traffic signals for each lane, and circuits for energizing the same; Aan electric motor operating at a predetermined time rate, and a shaft and switches operated thereby for energizing said signal circuits through continuous successive cycles, in each of which cycles the right-of-way signals for the lanes are energized alternately for predetermined periods of time; traic responsive means for one of said lanes having one condition of operation when traihc on the said one lane is approaching the said intersection and is within a certain distance thereof, and a second condition of operation for all other positions of trac on the said one lane with respect to the said intersection; relay means operatively associated with the circuits of the right-of-way signals for the other of said lanes and the corresponding motor-operated switches for controlling connection of the latter, said relay means having a normally de-energized condition for connecting the latter said circuits to the said corresponding switches, and an energized condition for disconnecting said latter circuits from said corresponding switches; an auxiliary circuit for energizing directly the right-of-way signals for the said one lane, including a switch closed by the said relay means in its energized condition; an operating circuit for the said relay means, including a switch closed by the ltraffic responsive means in its said one condition of operation and a switch closed by the said shaft in the right-of-way period for the said one lane for energizing said relay during said latter period; a stick circuit for maintaining said relay means energized, including a switch closed by the relay means in its energized condition and a switch closed by the tralic responsive means in its said one condition of operation; and a holding circuit for retaining the said relay means energized through the cycle until the beginning of the said following rightof way period for the said one lane when the traffic responsive means is restored into its second condition of operation during the periods in which the circuits of the right-of-way signals for the said other lanes are energized, including a switch closed by the said relay means in its energized condition, and a switch closed by the shaft at the end of the right-of-way period for the said one lane, which switch is retained closed f by the said shaft until the beginning of the said following right-of-way period for the said one lane.

SAMUEL S. STOLP.

FRANK H. RICHTERKESSING. 

